Process of treating comminuted wood, &amp;c.



" T patentin Great Britain,

UNITED STATES PATENT OFFIC ALEXANDER OLASSEN, OF AIX-LA-OHAPEL'LE,GERMANY.

PROCESS OF TREATING- COMMINUTED WOOD, 800.

SPECIFICATION forming part of Letters Patent No. 726,029, dated April21, 1903. Application filed August 30, 1902. Serial No. 121,676. (Nospecimens.)

To all whom it may concern:

Be it known that I, ALEXANDER CLAssEN, a citizen of Germany, residing at57 Tomplergraben,Aix-la-Ohapelle, in the Empireof Germany, have inventeda certain new and useful Process of Treating Comminuted Wood, 650., (forwhich I have applied for a datedAugust 6, 1902, No. 17,299,) of whichthe following is a specification.

My invention relates to a treatment of comminuted wood-such!as sawdust,shavings, or chips, peat, or the like cellu1osematerialwhereby it isbrought into a condition suitable for its consolidation by' pressureinto any desired form, such as briquets or slabs.

For this purpose I moisten the material to be treated with a'dilute acidhaving an effect on the -cellulose which causes the particles of thematerial to cohere when pressed together. Examples of suitable'acids arehydrochloric acid, nitric acid, sulfurous and sulfuric acid. Themoistened material is then introduced into a suitable vessel, preferablya drum revolving on a horizontal 'axis, lined with lead or othermaterial which will resist the attack of the acid used. The vessel isthen closed and heated externally or internally by introduction ofsuperheated or high-pressure steam, so as to raise the temperature to105 to 145 centigrade and to maintain it at this point for from thirtyto sixty minutes. The temperature and the time of the process maygreatly vary, though what I have just suggested would ordinarily producesatisfactory results. At the end of this time the-vessel is opened andthe mass lixiviated with water. The material is then dried, whereupon itis ready for compression into the desired consolidated form. By means ofthis treatment the elasticity of the material is removed and theparticles acquire the property of cohering under pressure without theuse of an agglntinant, so as to form a solid and exceedingly densebriquet or slab or piece of any desired shape, which has no tendency todisintegrate, but remains a permanent solid substance capable whensufficient pressure is used in forming it of receiving a high polish.This material may be used to make articles of manufacture which are nowmade of wood. It may be used for making insulating-fixtures forelectrical appliances, it may be converted into .charcoalfbdrned asfuel, or used in any other manner the nature of the material will permit. Itmay also be readily molded into ornamental designs for buildings,furniture, and the like. v

'The proportion of dilute acid to be added to the material depends onthe nature of the latter, but'should not be more than sufficient tothoroughly moisten the material. The degree of dilution of the'acid alsodepends on the nature of the material and on the nature of the acid; butI have found that for sawdust and for hydrochloric acid," for example, asolution containing about five per cent. of real acid is suitable. Forexample, when I use ordinary deal-sawdust I add one part, by weight, ofdilute hydrochloric acid containing about five per cent. of real acid tothree parts, by weight, of the sawdust.

The temperature selected for the treatment is chosen in relation to thedegree of consolidation required. The higher thetemperawill be thespecific gravity of the compressed product. If the temperature iscarried far over 145 centigrade,carbonization of the material willgenerally ensue.

The treatment of sawdust for producing sugar by heating it in a closedvessel with sulfurous acid and sulfuric acid under certain conditions isknown, and I do not claim such treatment; but,

Having thus described the nature of this invention and the best means Iknow of carrying the same into practical effect, I claim- The process oftreating comminuted Wood, peat or like cellulose material, whichconsists in moistening the material with acid, then heating themoistened materialTihtil theparticles have acquired the property ofcohering under pressure, then lixiviating said material, then drying andcompressing saidmaterial into a compact solid piece.

In testimony whereof I have hereunto set ture used within the limitsnamed the higher my hand in presence of two subscribing witnesses.

ALEXANDER OLASSEN.

Witnesses:

JOHN B. ADAMS, WILLIAM J. REUTERS.

